1. Field of the Invention
The invention relates to transport pallets particularly adapted to transporting heavy, bulky and fragile objects such as, for example, cabinets for processing electrical signals by means of integrated circuits. The invention applies particularly to pallets for transporting cabinets of data processing machines. Transportation ordinarily includes the operations of handling, transportation proper, and storage.
2. Description of the Related Art
An ordinary pallet is made from a load board which includes two decks connected to one another by deck spacers which allow the passage of lift-truck and pallet truck forks. The invention relates to non-reversible pallets with small load-bearing surfaces, intended for the specific uses mentioned above. Under these conditions, the lower deck forms a base and constitutes, along with the deck spacers, the means of support for the upper deck, which is simply called the deck. Thus, the deck and its means of support form a fixed, non-movable structure, which is of course capable of supporting the weight of the cabinet. When the load must be immobilized on the pallet, the pallet is provided with means for holding the load which form a collar or surrounding frame over the load. These means for holding the load are quite varied, and can be very sophisticated for specific uses.
Typical examples of prior art arrangements include U. S. Pat. Nos. 3,949,878 and 3,779,571; Belgium Patent 547,276 and German Patent 2,312,477.
Computer cabinets require very strict handling conditions which will emphasize the problems solved by the invention. First of all, these cabinets are very costly. They contain of electrical and electronic elements miniaturized to adapt to the very large scale integration of circuits in a semiconductor material, and to provide the shortest paths for very high frequency electrical signals. These components and their assembly are therefore fragile, and will not withstand intense shocks. They are also very sensitive to ambient conditions. For example, they must be protected from dust and kept in a dry atmosphere at a temperature which is not excessive. The cabinets are therefore packed in an impermeable sheath of strong plastic, which must be well protected in order to prevent its coming open during transport due to, for example, a lateral shock. Moreover, these cabinets are very heavy, on the order of 250 kg for average systems and more than 500 kg for very large multiprocessor information systems. Removing a cabinet from the pallet (depalletization) at its destination point thus poses many problems. The cabinet is released from the means for holding it on the pallet and placed on casters. This requires the involvement of several men, in order to have proper control of the movements of the cabinet on the very limited surface of the deck of the pallet, and to prevent shocks or overturning during the lowering of the cabinet. Rails to be used in lowering the cabinet are ordinarily supplied with the cabinet. However, considering the weight of the cabinet, it is necessary for these rails to be very resistant to bending and long enough to provide a slope which is not too steep, to avoid the risk of unbalancing the cabinet. The rails are therefore made of thick steel and constitute very heavy and bulky elements which must accompany the cabinet. The problems posed by the transport of these cabinets are therefore numerous and very constraining. Moreover, although they are fragile, their weights and volumes require them to be transported with large trucks, and persons charged with the handling of heavy equipment, such as machine-tools and the much more robust farming machines, are generally not very concerned with the precautions which must normally be taken for this kind of cabinet.